The SSO’s chief explains why he’s taken his time before conducting the music Beethoven never heard.

“This is the first time I’ve done Missa Solemnis. I waited until I was 57, which was Beethoven’s age when he died. That just feels like a clean break.”

David Robertson sits back with a coffee in his dressing room at the Sydney Opera House, relaxed, but with the score of Beethoven’s choral masterpiece sitting within easy reach on the piano in the corner. Through the walls we can hear Stuart Skelton, one of the impressive roster of soloists for tomorrow’s concert, practicing scales next door – surprisingly soothing, a bit like a Philip Glass CD on in the background.

The Sydney Symphony Orchestra’s Chief Conductor is no stranger to Beethoven – “I’ve done the Mass in C a number of times, Christ on the Mount of Olives, all the symphonies, I think all the overtures, The Creatures of Prometheus, all the orchestral concertos, so pretty much everything” – but the hour-and-a-half choral marathon that was to be the one work that the composer was never destined to hear in full has...